If you have a particular phobia of venomous things—creatures that bite, sting, or stab to deliver their venom and incapacitate or injure in defense or predation—then we highly suggest that you avoid the ocean. When we think of venomous creatures, we typically think of the more traditional ones like snakes, scorpions, spiders, and so on. There are, however, more venomous fish in the sea than there are venomous snakes on land and, in fact, the approximately 1,200 venomous fish species are more than the sum total of all the other known venomous vertebrates.

Among all the known venomous fish, the most deadly is the reef stonefish. The highly camouflaged fish rests among rocks, blending in and waiting for prey to swim by. Along its back is a row of 13 spines, each incredibly sharp, stiff, and shaped like a hypodermic needle connected to venom sacs in the back of the fish. The spines are so sharp that they’ve been known to pierce through boot soles and protective gear. Exposure to the venom in humans causes severe pain, shock, paralysis, and localized tissue death. Large doses can be fatal to humans, generally young children, the elderly, and those with weakened immune systems.